The present invention relates to a separating tool of a joining device for flexible packagings, in particular for tubular bag machines in which a sealing operation takes place using ultrasound technology.
Horizontal tubular bag machines are known from the prior art, in which the packaging materials are joined to one another using conventional joining methods or alternative joining methods, such as, e.g., ultrasound, wherein a separating of the packaging is carried out in addition to the joining process. Thus, the packaging material tube is divided into individual tubular bags in the case of tubular bag packagings.
The separating process takes place between the upper roller and the lower roller when conventional rotary heat and cold sealing is performed.
For that reason, the cutting blades are usually fixed by means of end face or lateral clamping screws in the cutting gap of a joining tool.
Particularly in the case of ultrasonic sealing on horizontal tubular bag machines, ultrasonic frequencies have to be transmitted to passively oscillating components, such as, e.g., the cutting blades or crush cutters, when sealing the head or foot seam as well as during the cutting process. This coupling of the exciter frequency leads to natural frequencies along the free lengths between the clampings. Under the influence of the crushing or cutting force, said natural frequencies can lead to component failure. The service life of the blades is therefore not limited by wear to the blade geometry but rather by a component failure by means of blade breakage.
In addition cutting methods are known which use power-actuated cutoff or guillotine blades. In these methods the cutting force and the cutting speed are generated with the aid of pneumatics, hydraulics, crank drive, etc.